Understanding and manipulating chronic Helicobacter pylori to enhance treatment

我们提出的研究重点是限制慢性病原体Heli抗生素敏感性的定义因素， 幽门螺杆菌有证据表明，慢性H。幽门螺杆菌是很难治愈的抗生素，因为它是在一个 至少部分受胃酸控制的缓慢生长状态。H.幽门螺杆菌的治疗依赖于清除酸， 包括强抗酸剂质子泵抑制剂（PPI）。PPI阻止了酸的产生，提高了stom- ach pH，并促进H.幽门生长细菌生长使标准抗生素更好地发挥作用。有一个 我们对H的确切性质的理解存在差距。幽门螺杆菌慢性生长状态，例如其代谢活性如何， 酸是否是唯一的生长抑制剂，以及什么类型的代谢H。幽门螺旋杆菌展开后生长 PPI治疗。这一点很重要，因为H。幽门螺杆菌感染在慢性状态下治疗。百万 全世界和美国有1000万人感染了H。pylori并患有相关疾病- 溃疡和胃癌。胃癌是全球第四大癌症死亡原因。H.幽门螺杆菌是一种 这是一个持续存在的问题，因为发达国家的发病率已经稳定下来。此外，目前的治疗方法， 治愈H.幽门螺杆菌感染失败的频率是不可接受的：美国最近的估计发现， 20-25%的受感染个体不能通过当前的治疗方案治愈。本项目的总体目标是-- 目的是了解H.幽门螺杆菌慢性生长状态，并使用这些信息来设计方法， 促进生长，从而提高抗生素敏感性。我们的中心假设，基于已发表的和初步的 数据，是大多数慢性状态H。幽门螺杆菌是在一个极端缓慢的增长模式，限制了 酸、翻译缺陷和营养限制的组合。在目标1中，我们将使用H的组合。 pylori突变体和小鼠模型来填补我们对H. pylori慢性生长状态， 生长速率，这些参数如何受PPI影响，以及PPI后倍增是否需要乳酸 利用率就像早期增殖一样。此外，我们还测试了增加关键碳源， 乳酸盐增强H.幽门螺杆菌慢性状态生长及抗生素治疗。在目标2中，我们以初步数据为基础， 生长缓慢的H。幽门螺杆菌显示出显著的翻译抑制，包括通过增加核糖 Mal沉默因子RsfS。我们使用分子生物学和生物化学来填补我们对RsfS理解的空白 功能的一般，并表征如何控制RsfS表达，以及其他翻译蛋白， tors，控制翻译和影响慢性殖民。该研究在假设上具有创新性 螺杆菌幽门螺杆菌慢性缓慢增长是由信号除了酸，并知道和靶向 这将促进更好的治疗。这项拟议中的研究意义重大，因为它将提供新的见解， 慢性生长的控制方法，并提供新的方法来提高H。幽门抗生素敏感性的 这项研究产生的长期结果将提供见解，为改善 将这些微生物推向对抗生素敏感的状态。

Our proposed research focuses on defining factors that limit antibiotic sensitivity of the chronic pathogen Heli- cobacter pylori. Evidence suggests that chronic H. pylori is difficult to cure with antibiotics because it is in a slow growth state controlled at least in part by stomach acid. H. pylori treatments rely on removing acid by in- cluding strong antacids called proton pump inhibitors (PPI). The PPI blocks acid production, raises the stom- ach pH, and promotes H. pylori growth. Bacterial growth allows standard antibiotics to work better. There is a gap in our understanding of the exact nature of the H. pylori chronic growth state, e.g. how active its metabo- lism is, whether acid is the only growth inhibitor, and what type of metabolism H. pylori deploys to grow after PPI treatment. This information is important because H. pylori infections are treated at the chronic state. Mil- lions of people worldwide and in the U.S. are infected by H. pylori and suffer from its associated diseases— ulcers and gastric cancer. Gastric cancer is the fourth leading cause of cancer deaths worldwide. H. pylori is an on-going problem, as the incidence has stabilized in the developed world. Furthermore, current therapies to cure H. pylori infection fail with unacceptable frequency: recent estimates in the United States have found that 20-25% of infected individuals are not cured by the current therapeutic regime. The overall objective of this ap- plication is to understand the H. pylori chronic growth state and use this information to design approaches that enhance growth and therefore antibiotic sensitivity. Our central hypothesis, based on published and preliminary data, is that the majority of chronic-state H. pylori are in an extreme slow growth mode, limited by a combination of acid, translational deficiency, and nutrient restriction. In Aim 1, we will use a combination of H. pylori mutants and mouse models to fill gaps in our understanding of the H. pylori chronic growth state and growth rate, how these parameters are affected by PPI, and whether post-PPI multiplication requires lactate utilization as early stage multiplication does. Additionally, we test whether increasing key carbon sources like lactate enhances H. pylori chronic state growth and antibiotic cure. In Aim 2, we build on preliminary data showing slow growth H. pylori display significant translational repression, including by increase in the riboso- mal silencing factor RsfS. We use molecular biology and biochemistry to fill gaps in our understanding of RsfS function in general, and to characterize how controlled RsfS expression, as well as other translational inhibi- tors, controls translation and affect chronic colonization. The proposed research is innovative in its hypothesis that H. pylori chronic slow growth is promoted by signals in addition to acid, and that knowing and targeting these will promote better cures. The proposed research is significant because it will provide new insights into ways that chronic growth is controlled and provide new ways to enhances H. pylori antibiotic sensitivity. The long-term outcomes generated by this research will provide insights that will lay the groundwork for improved therapies that push these microbes into an antibiotic-sensitive state.